1. Field of the Invention
The present invention relates generally to helium-cadmium laser devices, and more particularly to a helium-cadmium laser that is designed to lase at 353.6 nm.
2. Description of the Prior Art
The characteristics of helium-cadmium (HeCd) laser devices are well known. Observable lasing transition lines have been identified at the wavelengths 325.0 nm and 441.6 nm in a positive column HeCd laser. Additional lasing transitional lines at the wavelengths 533.7 nm, 537.8 nm, 635.5 nm, 636.0 nm and others in the infrared have been observed in a hollow cathode discharge HeCd laser. There exists, however, a less well-known potential laser transition line at 353.6 nm, which was suggested by J. P. Goldsborough in the IEEE Journal of Quantum Electronics, Volume QE-5, Number 2, February, 1969, Page 133. This 353.6 nm line has never been observed to lase, apparently because the initial atomic energy level which characterizes the 325.0 nm line is the same initial level as that which characterizes the 353.6 nm line, and the 325.0 nm transition is strongly favored probabilistically for lasing over the transition producing the 353.6 nm line. Thus, although the theoretical possibility of the 353.6 nm line, as a lasing transition, was suggested in 1969, there has apparently been no laser device reported which successfully lases at the transition resulting in the 353.6 nm line.